The least expensive camcorders with a mic jack are the Canon ZR800, ZR900 and ZR930. They do not have manual audio control. They are miniDV tape based. They do standard definition DV only.
The least expensive camcorders with a mic jack and manual audio control are the Canon HV20, HV30, Sony HDR-HC7 and HC9. They are miniDV tape based. They do standard definition DV and high definition HDV. They have optional tele lenses - but generally only up to 2x - and typically without the tele lens are only 10x-12x. You are wise to disable digital zoom. The Sonys have "SuperNightShot". There is an infrared LED on the camcorder that can illuminate an area up to about 10-12 feet away, so you can record monochromatic (green/white) video in zero visible light. External IR LED lights are optionally available to increase this to about 25 feet.
Sony does not "retain the microphone port in all media". The newer standard definition camcorders do not have the Sony proprietary "Active Interface Shoe" that uses only Sony proprietary mics.
Big lenses and big glass and big imaging chips make for big zoom AND good low-light behavior. In my opinion, you will not find what you want in a consumer camcorder, regardless of media type, in the price range you have stated. If that were the case, the professionals would not need to spend the money they do on their cameras. They, like everyone else are always looking for ways to not spend money (it lets them use that available money for other things).
Using a tripod or some sort of solid stable surface of such closeups to which you refer is a requirement. Humans were not built to remain still - and when zoomed in on something, hand-held video will not be very steady. No amount of Optical or Electronic Image Stabilization in the camcorder will fix this.
MiniDV tape is indeed best quality - who cares if they are "old technology" if they are best quality? The reason they are best quality is because of the format to which they store the video - DV and HDV. This can be done with an external hard drive from FireStore or using a Panasonic camcorder that uses P2 cards (HDX200). Both are outside your budget - but both will store in DV or HDV. And the FireStore drive requires a miniDV tape based camcorder because it connects to the camcorder's firewire port.
MiniDV tape - at ~$3 per hour of video is expensive? Sorry - I have to disagree. As a digital archive method (the original tape is the archive - do not reuse tapes), it is the least expensive and stable method available.
DVD based camcorders can indeed pose challenges for editing. In my opinion, consumer based DVD camcorders compress video way too much to provide any useful video for editing. I believe you really want to start with the LEAST compression for capture... then downstream, you can pick the compression you want for the different media you want to use. To compress a LOT in the first step is just a bad idea... video compression = discarded video data = reduced video quality.
I think your point 5 refers to "hard drive" - this would be, technically, "hard disc drive" or HDD. Referring to "HD" in the context of video is usually a reference to "High Definition". Yes, they are occasional HDD buffer issues, they are generally due to lots of vibration due to really loud audio or the camcorder touching something vibrating or the drop sensor doing its job. Removing the source of the vibration (or drop) and the buffer issues go away. Memory can be limited because the HDD allows for finite space, but some of them have pretty large internal HDDs for many hours of storage. That the internal HDD camcorders store such a highly compressed MPEG2 file has them fall off my list. Flash memory camcorders use a similar compression, but at least the memory cards can be replaced when full... but they can be expensive.
I regret that I have no recommendation of a "dream camcorder" for you that meets all your requirements. You need to either reduce your requirements or increase your budget.
In either case, I would suggest that you stay in either the miniDV tape environment or the flash memory environment because all you need to do is buy more memory (cards or tape) and take it with you.
If you reduce your requirements:
The Canon FS10, FS11 and FS100 use flash memory - and can record video to either the built-in flash memory or optional SDHC memory cards. All three also have a 1/8" (3.5 mm) mic-in jack. "Night vision" will be iffy. They have at least 37x optical zoom. They do not have the buffer issues associated with HDD camcorders. They store highly compressed MPEG2 video. They are considered "standard definition" camcorders. They use a single imaging chip. Whether your editing setup can deal with these highly compressed video files is unknown. The trick is getting the video to be useful in your computer - once that is done, the DVD process is downstream and you can control that part. I don't think they have manual audio control. Video file transfer is accomplished by copying the video data files over USB connection. Since there is no "automatic archive" as in the tape environment, the first step after copying the video data files from the flash memory to the computer should be to burn a bunch of data DVDs or copy the unedited files to another drive before deleting the files from the memory cards to be used on the next project.
Optionally, the Canon ZR800, ZR900 and ZR930 have a mic-in jack, use miniDV tape, have similar zoom to the Canon FS-series, are standard definition camcorders and will work with Windows MovieMaker - if you can get the video into the computer. Your computer requires a firewire port. If it does not have one, they are typically easy (and cheap) to add. We do not know your computer's hardware platform, so it is impossible to know for sure.
If you increase your budget:
Sony HDR-FX7, HVR-V1U or Canon XHA1. They are miniDV tape based camcorders. They are considered "prosumer" (actually, the V1U is the pro version of the FX7) In either case, an additional 2x tele-lens is required to get you from the built-in 20x optical zoom to 40x. They are 3-chip cameras and their video quality is what you see in documentaries. All three are high definition (1080i) camcorders and can also shoot standard definition. While the Sony HDR-FX1 (or its pro sibling the HVR-Z1U) have better low-light capabilities, they have only 12x zoom, so they fall off your list - even if you add a 2x tele lens. Yes, all these camcorders have a mic-in jack. These camcorders are larger than "normal" consumer camcorders, but their video quality is a LOT better. Microsoft MovieMaker does not deal with HDV. A video editing application capable of using HDV format video (like Sony Vegas) would be required. Your computer will also require a firewire port (previously discussed).
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